Device for shifting pinion on starting motor



Feb. 21, 1967 AKIRA TAKAMI 3,304,790

DEVICE FOR SHIFTING PINION ON STARTING MOTOR Filed April 16, 1965 FIG.

United States Patent 3,304,790 DEVICE FOR SHIFTING PINION ON STARTING MOTOR Airira Talrami, Tokyo, Japan, assignor t0 Mitsubishi Denkl Kahushiki-Kaisha, Chiyoda-ku, Tokyo, Japan Filed Apr. 16, 1965, Ser. No. 448,306 Claims priority, application Japan, Apr. 30, 1964, 39/2 3,503 2 Claims. (Cl. 74-6) This invention relates to a device for shifting a pinion on a starting motor for use with an internal combustion engine, wherein the pinion is adapted to shift by a lever actuated by an electromagnet.

In general, a pinion shifting device is operative to move a pinion slidably fitted onto a rotatory shaft of a starting motor for use with an internal combustion engine, toward a stand still ring gear on the engine for meshing. However, only movement of the pinion toward the ring gear hardly leads to meshing thereof and usually causes the end face of the pinion to abut against the end face of the ring gear resulting in the impossibility of meshing the pinion with the ring gear. Heretofore it has been commonly practiced to first press the pinion against the end face of the ring gear under an appropriate pressure when the pinion abuts against the ring gear at their end faces without meshing and then to rotate the starting motor thereby to bring the pinion into its position at which the same can mesh the ring gear. Thereupon the pinion is put in mesh with the ring gear.

In the conventional type of pinion shifting devices including a lever for shifting a pinion on the associated starting motor, spring means are disposed between the pinion and the lever and adapted to be compressed upon the pinion abutting against a ring gear on the associated internal combustion engine at their end faces. This compress of the spring means presses the pinion against the ring gear under an appropriate pres-sure and also are accompanied by swivellin-g movement of the lever. This leads to actuation of a switch operatively coupled to the lever resulting in rotational movement of the starting motor.

This measure requires to accomplish the abovementioned swivelling movement of the lever through compression of the spring along the axis of the rotatory shaft of the starting motor. Therefore, the rotatory shaft of the starting motor should have its axial dimension sufficient to permit the spring to be sufficiently compressed. This leads to the disadvantages such as a large axial dimension of the starting motor and a large size thereof.

Accordingly it is the primary object of the invention to eliminate the abovementioned disadvantages of the conventional type of pinion shifting devices.

It is another object of the invention to provide a new and improved device for shifting a pinion on the associated starting motor for use with an internal combustion engine wherein the starting motor is allowed to reduce in axial dimension to a great extent resulting in a small-sized construction.

It is a further object of the invention to provide a new and improved pinion shifting device of the type described in the preceding paragraph, and simple, rugged and durable in construction.

With the aforesaid objects in view, the invention resides in a device for shifting a pinion on the associated starting motor for use with an internal combustion engine, said device comprising a pinion slidably mounted on the rotatory shaft of the starting motor and opposing to a ring gear on the engine, a pinion shifting sleeve fitted onto the rotatory shaft of the starting motor for axial sliding movement and operatively connected to the pinion, electromagnet means including a plunger movable substantially parallel to the axis of the rotatory shaft, a pinion shifting lever member having one end pivotably engaging the pinion shifting sleeve and the other end pivotably engaging the plunger, 21 support member for pivotably carrying the pinion shifting lever member and movable in the axial direction of the rotatory shaft of the starting motor, compression spring means operative to normally bias the support member to one position and to oppose movement of the support member toward the other position. When the pinion abuts against the ring gear at their end faces without meshing upon energization of the electromagnet means, the compression spring means tend to swivel the pinion shifting lever member in a direction to mesh the pinion with the ring gear. Then when the starting motor is rotated the pinion is put in mesh with the ring gear by the action of the spring means.

The invention as to its organization and the manner of operation as well as other objects and advantages thereof will be clearly understood from the following description taken in conjunction with the accompanying drawings in which:

FIG. 1 is a fragmentary elevational view, partly in section of a pinion shifting device constructed in accordance with the teachings of the invention;

FIG. 2 is a sectional view taken along the line IIH of FIG. 1;

FIG. 3 is a sectional view taken along the line III- III of FIG. 1; and

FIGS. 4a through 4d are diagrammatic views useful for explaining the operation of the invention.

Throughout figures the like reference numerals designate the corresponding components.

Referring now to FIG. 1, there is illustrated a pinion shifting device constructed in accordance with the teachings of the invention. The arrangement illustrated comprises a starting motor generally designated by the reference numeral 1% including a yoke 11, a field core 12, a field Winding 13, a front bracket or pinion housing 14 mounted on the open end of the yoke 11, a rotatory shaft 15 rotatably journalled at one end to the bracket 14 and at the other end to another bracket (not shown), an armature core 16 rigidly secured on the rotatory shaft 15 and an armature winding 17 inductively disposed on the armature core 16.

The rotary shaft 15 of the starting motor 10 has a pinion shifting sleeve 18 spline fitted onto that portion thereof projecting beyond the armature winding 17, through a helical spline element 19 for axially sliding movement, and a pinion 2t loosely mounted on the rotatory shaft 15 and rigidly secured to the righthand end as viewed in FIG. 1 of the pinion shifting sleeve 18 through an overrunning clutch 21. The pinion 20 is arranged to be shiftable along the rotary shaft 15 toward the righthand thereof to mesh a ring gear on the associated internal combustion engine in the manner as will be described. The ring gear is shown in FIG. 1 as a part 22 disposed so as to extend from an opening 23 formed on the lower end portion of the pinion housing 14 into the interior of the latter in opposed relationship to the pinion 20. To limit the rightward movement as viewed in FIG. 1 of the pinion 20 to a stopper ring 24 is rigidly secured on the rotatory shaft 15 near the inner end portion of the pinion housing 14.

The pinion shifting sleeve 13 is provided on the intermediate portion with a peripheral groove 25 for the purpose as will become apparent hereinafter.

As shown in FIGS. 1 and 2, the pinion housing 14 is provided with a plunger housing 26 at its upper portion. The plunger housing 26 has a circular cross section which is open at its one end where a casing 27 is rigidly secured. The casing 27 is made of any suitable magnetic materials. Disposed Within the casing 27 is an electro- -shown) magnet device generally designated by the reference numeral 28. The electromagnet device 28 comprises an electromagnetic winding 29 of cylindrical form wound around a spool 30 disposed within the casing 27 and a plunger 31 movably disposed in the central bore of the spool 33 and hence of the electromagnetic winding 29 and extending in substantially the same direction as the rotary shaft 15 of the starting motor 10. The plunger 31 extends through the bottom part 32 of the casing 27 into the interior of the plunger housing 26 and has a collar 33 formed on that portion thereof extending into the interior of the housing. A reset spring 34 in the form of a helix is disposed around the plunger 31 between the bottom part 32 and the collar 33. The plunger 31 also has a peripheral groove 35 formed thereon between the reset spring 34 and the projecting end thereof.

As best shown in FIG. 2 the pinion housing 14 is integrally connected to the plunger housing 26 by a connection 36 which has an axially extended support bore 37 centrally formed therein and open at the lefthand end as viewed in FIG. 1 (see also FIG. 3). This support bore 37 serves to rotatably support a cylindrical support member 38 for the purpose as will be apparent thereinafter. As shown in FIGS. 2 and 3, a diametrical cut 39 extending axially from one side of the support member opposite to the closed end of bore 37 toward the other end portion of the support member. Through the cut 39 loosely extends a pinion shifting lever member 40 pivotably mounted to the support member 38 by a pivot pin 41 disposed perpendicularly to the central plane of the cut 39 in the support member 38 as shown in FIGS. 2 and 3. The cut 39 has preferably a dimension just sufiicient to permit the lever 40 to swivel about the pin 41. The lever 40 has one end portion 42 pivotably engaging the periphereal groove on the pinion shifting sleeve 18 and the other end portion 43 pivotably engaging the peripheral groove 35 on the plunger 31 of the electromagnet device 23. As best shown in FIG. 2, each end portion 42 or 43 of the lever 40 is furcated so that the associated reduced portion 25 or 35 is sandwiched between two furcated leg portions.

Disposed within the support bore 37 is helical spring 44 of helical shape serving to normally bias the support member 38 to one position at which the member abuts against the closed end of the bore or to its righthand position as viewed in FIGS. 1 and 3. That end of the spring 44 remote from the support member 38 is received .by a receiving cover 45 which also serves to close the open end of the bore 37. The cover is maintained at its position determined by the righthand end surface as viewed in FIG. 1 of the yoke 11 and the outer bottom surface of the casing 27 facing the interior of the clutch housing 14 with both surfaces substantially flush with each other.

As shown in FIG. 1 the lefthand end of the pinion shifting sleeve 18 normally engages a step 46 formed on the rotatory shaft 15 of the starting motor 10.

The arrangement thus far described is operated as follows: In FIG. 1 it is to be noted that the various movable components are shown as being in their initial positions assuming before an internal combustion engine represented by the ring gear 22 is started. Upon starting the engine a starting switch (not shown) is closed to energize the electromagnetic winding 29 of the electromagnet device 28 from a source of electric power (not The energization of the winding 29 causes the plunger 31 to be drawn into the longitudinal hole of the spool 30 or to effect leftward movement as viewed in FIG. l, against the action of the spring 34. This permits the pinion shifting lever 40 to swivel in the counterclockwise direction as viewed in FIG. 1 about the pivot pin 41 thereby to move the pinion 20 along the rotatory shaft 15 of the starting motor toward the ring gear 22 on the engine,

Under these circumstances, the teeth on the pinion 20 may very frequently abut against the teeth on the ring gear 22 at their opposed end faces but not in meshing relationship. The operation of the invention performed in this assumed conditions will now be described in conjunction with FIGS. 4a to 4d wherein the reference line aa is illustrated extending along that surface of the cover 45 bearing the spring 44 and another reference line bb illustrated extending along the longitudinal axis of the support member 38. FIGS. 4a to 4d illustrate movement of both lever and springs 40 and 44 relative to those reference lines respectively.

Before the electromagnet device 28 is energized the end portion 43 of the pinion shifting lever 40 engaging the plunger 31 is spaced away from the reference line aa a. distance L and the spring 44 has its normal length of 1 on the reference line bb as shown in FIG. 4a. When the electromagnet device 28 is energized, the lever 40 is swivelled in the counterclockwise direction as viewed in FIG. 4a to shift the pinion shifting sleeve 18 rightwardly until the teeth on the pinion 20 a but against those on the ring gear 22 at their end faces. This is illustrated in FIG. 4b wherein the end portion 43 of the lever 40 is spaced away from the ref erence line a--a a smaller distance of L while the spring 44 has still normal length of 1 Under these circumstances, the plunger 31 has not yet completed to move its entire stroke. This means that starting switch (not shown) adapted to be closed upon the plunger having completed to move its entire stroke thereby to complete a circuit for energizing the starting motor is not closed and therefore the starting motor is maintained hault.

Then the lever 40' is further swivelled to its position illustrated in FIG. 40 wherein the same has been swivelled in the counterclockwise direction as viewed in FIG. 4c about that end portion 42 of the lever engaging the pinion shifting sleeve 18 to its position illustrated in FIG. 4b while compressing the spring 44. Under these circumstances, the end portion 43 of the lever 40 is spaced away from the reference line aa a further smaller distance of L and the spring 44 reduces in length from the normal magnitude l to a smaller magnitude l on the reference line bb. In its position illustrated in FIG. 4c the plunger 31 has moved the entire stroke whereupon the starting switch (not shown) is closed to complete the circuit with the starting motor with the result that the motor is started.

On the other hand, the support member 38 has moved in the leftwise direction as viewed in FIG. 40 against the action of the compression spring 44. This movement of the support member 38 causes the spring 44 to be compressed whereby the pinion 20 presses against the ring gear 22 at their abutting end faces under an appropriate pushing pressure due to the compression of the spring 44. Therefore it will be appreciated that after the motor has been driven in the manner just described, the pinion 20 can oppose to the ring gear 22 in possible mesh relationship. As soon as the pinion 20 has opposed to the ring gear 22 in such relationship, the pinion 20 meshes the ring gear 22 to effect further rightward movement until the same engage the stopper ring 24. On the other hand, the lever 40 is allowed to additionally swivel in the counterclockwise direction about the end portion 43 thereof to its position illustrated in FIG. 4d. At the same time, the compression spring 44 returns to its initial position while the support member 38 is spaced away from the reference line aa initial distance I as shown in FIG. 4d. Thus the starting motor '10 initiates the operation of the associated engine in the well known manner.

After the completion of start of the engine, the electromagnet device 28 can be deenergized to interrupt the supply to the starting motor 10 whereupon the reset spring 34 returns back to its initial position and therefore the lever 40 and the pinion 20' return back to their initial positions illustrated in FIG. 1.

It will be appreciated that there may very rarely occur the ideal case where the lever 40 at its position illustrated in FIG. 4a will swivel to directly mesh the pinion 20 with the ring gear 22 without both components abutting against each other. In this case, the lever 40 can move from its initial position illustrated in FIG. 1 directly to its position illustrated in FIG. 4d to permit the starting motor to start the engine while the same does not eifect the leftward movement of the support member 38 against the action of the spring 44.

It is readily understood that during rightward movement of the pinion shifting sleeve 18, the helical spline 19 serves to slowly rotate the sleeve while moving it in the righthand direction as viewed in FIG. 1 thereby to facilitate meshing of the pinion 20 with the ring gear 22.

From the foregoing it will be appreciated that the device of the invention includes the spring disposed on the pivot unit for the pinion shifting lever for the purpose that, when the pinion abuts against the ring gear at their end faces, the lever is permitted to further swivel to mesh the pinion with the ring gear. Accordingly, when the pinion has abutted against the ring gear at their end faces, the pivot unit for the lever is moved about that portion of the lever engaging the pinion shifting sleeve whereby the lever swivels in the direction to mesh the pinion with the ring gear. On the contrast, the prior art type device includes disposed around the outer periphery of the pinion shifting sleeve a spring serving to move the pinion shifting lever along the sleeve when the pinion abuts against the ring gear. Therefore, it is apparent that the present invention permits the axial dimension of the pinion shifting sleeve and hence the starting motor to greatly decrease as compared with the prior art type devices above described. This leads to much saving of materials for the pinion shifting sleeve, the rotary shaft of the starting motor, the pinion housing, etc. The decrease in axial dimension of the pinion shifting sleeve, results in a decrease in its weight leading to an increase in mechanical durability of the rotatory shaft and bearing units therefor.

Since the spring serving to effect a further swivelling movement of the pinion shifting lever is disposed on the lever pivoting part that is, on a normally stationary part, the pinion shifting sleeve or a rotatable part becomes very simple and robust as compared with the conventional devices including such a spring disposed around the outer periphery of the pinion shifting sleeve or a rotatable part. This also contributes to an increase in durability of the device.

As previously described, the support member 38 is rotatably disposed in the connecting portion 26 connecting the pinion housing 14 to the plunger housing 26. With 6 this arrangement the pinion shifting lever 40 can effec completely operative connection of the shifting sleeve 12 and the plunger 31 even though the axes of the sleev and plunger would not be in parallel relationship or it a common plane. Therefore, the lever can sm0otl1l transfer the motion of the plunger to the pinion shift ing sleeve.

What is claimed is:

1. A device for shifting a pinion on the shaft of 2 starting motor for an internal combustion engine, saic pinion being axially movable on said shaft into engagement with a ring gear on the engine; said device comprising a pinion shifting sleeve on said shaft and connected with said pinion for axial movement therewith, a pinion shifting lever having one end pivotally engaging said pinion shifting sleeve, a cylindrical supporting member having an axially extending diametrical slot receiving an intermediate portion of said pinion shifting lever, a pivot pin extending across said slot and through said pinion shifting lever to support said lever pivotally in said supporting member, bearing means for supporting said supporting member for rotational movement and for axial movement approximately parallel to said shaft, stop means engageable with said supporting member in one direction, electromagnetic means connected with the other end of said pinion shifting lever and operable to move said lever about its pivot in a direction to move said pinion toward said ring gear, and spring means yieldably pressing said supporting member against said stop means and yieldably resisting axial movement of said support member away from said stop means, said spring means being yieldable to permit axial movement of said supporting member when said pinion abuts said ring gear without meshing therewith upon actuation of said electromagnetic means.

2. A device according to claim 1, in which said hearing means comprises opposite cylindrical surfaces embracing opposite sides of said cylindrical supporting member to support it for rotational and axial movement, with spaces between said surfaces for accommodating movement of said pinion shifting lever References Cited by the Examiner UNITED STATES PATENTS 1,844,000 2/1932 Whitney 74-6 2,839,935 6/1958 Hartzell et al. 746 2,947,179 8/1960 Lafitte 746 2,960,879 11/1960 Lafitte 74-6 FOREIGN PATENTS 837,530 6/1960 Great Britain.

MILTON KAUFMAN, Primary Examiner. 

1. A DEVICE FOR SHIFTING A PINION ON THE SHAFT OF A STARTING MOTOR FOR AN INTERNAL COMBUSTION ENGINE, SAID PINION BEING AXIALLY MOVABLE ON SAID SHAFT INTO ENGAGEMENT WITH A RING GEAR ON THE ENGINE; SAID DEVICE COMPRISING A PINION SHIFTING SLEEVE ON SAID SHAFT AND CONNECTED WITH SAID PINION FOR AXIAL MOVEMENT THEREWITH, A PINION SHIFTING LEVER HAVING ONE END PIVOTALLY ENGAGING SAID PINION SHIFTING SLEEVE, A CYLINDRICAL SUPPORTING MEMBER HAVING AN AXIALLY EXTENDING DIAMETRICAL SLOT RECEIVING AN INTERMEDIATE PORTION OF SAID PINION SHIFTING LEVER, A PIVOT PIN EXTENDING ACROSS SAID SLOT AND THROUGH SAID PINION SHIFTING LEVER TO SUPPORT SAID LEVER PIVOTALLY IN SAID SUPPORTING MEMBER, BEARING MEANS FOR SUPPORTING SAID SUPPORTING MEMBER FOR ROTATIONAL MOVEMENT AND FOR AXIAL MOVEMENT APPROXIMATELY PARALLEL TO SAID SHAFT, STOP MEANS ENGAGEABLE WITH SAID SUPPORTING MEMBER IN ONE DIRECTION, ELECTROMAGNETIC MEANS CONNECTED 